Compiling a framework gives the following (slightly reformatted) error:
/Users/mehely/Library/Developer/Xcode/DerivedData/<projectName>-cqcwkxegxcnodnetymctxgcbzdxy/Build/Intermediates/<projectName>.build/Release-iphonesimulator/<projectName>.build/Script-2901613518E1S7AF0061D14E.sh: line 97:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/libtool: No such file or directory
.
I used to fix this error by copying libtool from
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/
but inside XCode 7 iPhoneOS.paltform, libtool is not anymore present:
I can get libtool from older versions of XCode, but I cannot be sure whether it is the same version of the binary. What is the correct approach to solve this?

As you are using Xcode 7, the libtool is located in the following path:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool
What you can do here is simply copy it, and then paste it to the error's specified location:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/libtoolYou should also paste the file in the following path if you are planing to run the app on a device:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/libtoolif you didn't find the usr/bin just create a folder and call it usr, and another one inside it and call it bin. the paste the libtool inside it.